The collection of crosses, each one bearing a red heart, took Zanis two days to make. His son organized a GoFundMe page to assist with the trip to Nevada, which raised close to $5000 and garnered dozens of emotional comments.

"Sir, I don't know you in person, but I know you are doing something that cannot have a price," wrote one visitor to the page.

3 Las Vegas Shooting Stories That Need to Be Heard

This isn’t the first time Zanis has made such a gesture. He brought crosses to Columbine High School, the Boston Marathon bombing, the Orlando nightclub shooting –- and, according to the Chicago Sun-Times, earlier this year, he began a project of erecting crosses in a grassy local lot.

Each represents a homicide victim killed in Chicago in 2017, and another will be added for every person who’s killed in the city this year, he says.

Zanis tells the news outlet that he made his first cross 20 years ago when his father-in-law was killed.

“That just changed my life,” he says. “My first cross was for somebody that I loved. And when I put up these crosses here, I always think of my personal loss here too. Always.”